314 THE CANADIAN ENTOMOLOGIST 



pitted and as growth continues, the body is arched upwards be- 

 coming quite convex. 



In the latitude of Southern Wisconsin development continues 

 with great rapidity during May and early June, the ovisac becom- 

 ing distended with eggs. Within three weeks the females stop 

 feeding and a week later oviposition commences. Scattered .in- 

 dividuals begin egg laying by May 25 but the majority not until 

 June 11. The eggs are deposited beneath the scale in a cavity 

 or brood chamber formed by the shrinking ovisac, and this pro- 

 cess continues until the venter becomes fused with the dorsum. 

 At the end of egg laying the parent insect remains as a mere shell, 

 which acts as a barrier against various egg predators and parasites. 



The number of eggs laid by a single female varies considerably 

 and over two thousand have been counted^. Small individuals 

 may contain only a few hundred, but the-average number is con- 

 siderably over a thousand. 



The oviposition period terminates by the middle of June, and 

 eggs under observation on different hosts began to hatch during 

 the first days of July, although in one exceptional instance one 

 female was found to contain hatching young June 12. July 5 

 Lecanium corni was found hatching on ash, linden and apple, and 

 a few 'days later on bittersweet. Practically all the young had 

 issued by July 1 in spite of the fact that the dates of oviposition 

 extended nearly a month. The young remain under the old scale 

 until it becomes loosened, which is usually about five days from 

 the time the first eggs hatch. This short period of rest is not essen- 

 tial to the life of the insect, and when a scale is removed from 

 hatching young they immediately migrate to the leaves. They 

 generally settle on the underside and when numerous attach them- 

 selves along the principal veins, where they remain until autumn. 



Just before the leaves fall the immature scales migrate back 

 to the bark, having moulted once. The percentage of those suc- 

 cessful in re-establishing themselves in this way is not known, 

 and it is possible that many are distributed to different hosts by 

 the scattering of the leaves. 



Description. — The eggs are oval, and protected by a powdery 

 wax deposit, measuring .246 mm. by .112 mm. They are pure 



9. Lowe, V. H., Rep. N. Y. State Exp. No. 14, 1895. 



